The sum of two numbers is $74$, and their difference is $10$. What are the two numbers?
Answer: Let $x$ be the first number, and let $y$ be the second number. The system of equations is: ${x+y = 74}$ ${x-y = 10}$ Solve for $x$ and $y$ using elimination. Add the top and bottom equations together. $ 2x = 84 $ $ x = \dfrac{84}{2} $ ${x = 42}$ Now that you know ${x = 42}$ , plug it back into $ {x+y = 74}$ to find $y$ ${(42)}{ + y = 74}$ ${y = 32}$ You can also plug ${x = 42}$ into $ {x-y = 10}$ and get the same answer for $y$ ${(42)}{ - y = 10}$ ${y = 32}$ Therefore, the larger number is $42$, and the smaller number is $32$.